Packaged Rooftop Units
A packaged RTU puts the compressor, coils, blower, and heating section in one weatherproof cabinet that sits on the roof and ducts straight down into the space. Retail centers, strip malls, and single story offices rely on them because they're simple to service and replace. When buying, match tonnage to a fresh load calculation rather than the old nameplate, since many older buildings run oversized units. Also check whether you need gas heat, electric heat, or a heat pump model. Most owners buy new, because refurbished RTUs carry unknown compressor hours and refrigerant history.